For built camshafts, welded and drawn tubes have usually been used so far, which have been mounted in the internal combustion engine by means of a corresponding sliding bearing. The use of welded and then drawn tubes was not possible until now for roller-bearing-mounted and built camshafts, since the rolling bodies of the roller bearing ran directly on a shaft outer face and until now it was only possible to achieve the necessary surface hardness values and wear resistance with seamlessly drawn tubes with a higher carbon content. In this case the shaft outer face that formed the rolling body running face had to be hardened, for which a carbon content of the material of the shaft tube of more than 0.45% by mass was absolutely necessary. However, it was not possible to weld tubes having such a high carbon content.